Many jurisdictions presently face a crisis in the disposal of deadstock, offal and manure produced by the livestock industries. Disposal in landfill or burial sites is of course highly undesirable since any pathogens remain in the soil and since the breakdown of the products is uncontrolled and can lead to contamination. Many landfill sites do not accept deadstock or offal and in many cases those that do require high charges for disposal fees.
Uncontrolled disposal can lead to the risk of disease transmission to, and via, scavengers, insects, and the population at large. Composting either can require opening carcasses or carcass pathogen escape as carcasses decompose and can produce contamination and unpleasant odours.
The disposal of manure from hogs is problematic in view of the facts that it is primarily a slurry containing relatively high levels of water so that combustion is typically unavailable as a best method for disposal. Spread of the material on fields is costly and can lead to contamination.
There are combustion devices available for carrying out combustion of deadstock and animal parts. Many of the machines are batch processes at relatively low productions rates so the individual animals must be inserted into a containers and combustion carried out until the materials are destroyed and expelled through flue gases leaving some solid materials for collection and potential use. Often larger animal carcasses require dissection or dismembering. Such batch processes generally require the addition of fossil fuels to commence, and often to maintain the combustion at the temperatures required, even though in many cases the materials to be combusted generally have sufficient energy contained to maintain the combustion through the process, provided the system is managed properly. If additional fuel is therefore used, excess energy is produced in some situations leading to inefficiency.